This invention concerns a swaging machine suitable to work either according to the movement of a camera shutter or with a straight movement.
Swaging machines are known which have the task of producing forged parts by continuous progressive swaging. Such machines are structured according to the specific movement which characterizes their swaging action.
There are two methods for performing the swaging action; these methods depend on the characteristics which are to be obtained in the finished product.
One type of swaging machine carries out a straight movement and is more suitable to produce simple parts such as square, flat or hexagonal parts, etc.
The other type of swaging machine performs a circular movement, and hammers cooperate with each other like the components of a diaphragm of a shutter, that is to say, each hammer moves according to an arc of a circumference. This type of swaging is more suitable for processing round and cylindrical parts in general.
The text US-A-3,837,209 discloses a multipurpose forging machine according to the preamble of claim 1. This forging machine comprises a main piston able to move in a cylinder and coupled by a thrust pin to a second piston equipped at one end with a ram.
The second piston slides in a guide element pivoted at one side and connected to a pull-back cylinder on the other side.
Moreover, seatings are machined in the guide element and contain third pistons acting on the other end of the second piston.
In the method of working as a ram the second piston is rendered solidly fixed to the guide element by the thrust of the third pistons and therefore a thrust carried out by the first piston is imparted to the ram according to a circular movement.
The pull-back cylinder recalls the ram and therefore the second and first pistons to their initial position.
In the linear working method the pull-back cylinder is actuated until it causes the guide element to abut against a stop provided on the body of the forging machine.
The pull-back cylinder maintains this position and overcomes even the force exerted by the third pistons.
The main piston can therefore exert its own force directly on the second piston that bears the ram.
Return to the initial position is ensured by the third pistons.
This forging maching entails a series of drawbacks and shortcomings due to the following factors:
in the linear working method the unevennesses on the piece to be forged cause recoils of the second piston onto the guide element, these recoils causing swift wear of the second piston and of the guide element, which undergo drawing friction;
the third pistons are contained in seatings provided in the guide element, which is held in the body of the machine and can move during the method of working as a ram.
This entails the inclusion of a series of pipes arriving from outside for the passage of liquid and constantly subjected to considerable dynamic stresses, which result also in breakage of the pipes.